1. Field of the Invention
The invention relates to an oral treatment to reduce or to eliminate kidney stones, and to reduce the likelihood of their recurrence with a maintenance oral therapy.
2. Description of Related Art
Kidney stones represent a widespread, painful medical problem that is believed to have increased over the last few decades, particularly among Caucasian males in the United States and other predominantly Caucasian-populated nations. The most common type of kidney stone, or renal stone, is idiopathic in origin and generally calcareous. In contrast to the normal biomineralization of bones and teeth, the calcium oxalate biomineralization which is believed to cause renal stones contributes significantly to the cost of health care in the United States. Problems associated with renal stones not only include the perception of pain in the afflicted patient, but also mechanical irritation and compromise of renal tissue, back-pressure from restricted urine flow, and risk of infection due to mechanical irritation or back-pressure or to the mere presence of a foreign body in the kidney.
Ironically, it is believed that crystallization within the urinary tract occurs on an ongoing basis, with the formation of small crystals' providing the usual excretory function for eliminating calcareous stone salts. It is when such crystallization is not restricted to the urinary tract that the formation of unwanted crystalline stones in the kidney occurs. There are various theories as to why the crystallization is not restricted to the urinary tract in certain individuals, including genetic and dietary causes, but ultimately the cause of renal stones is not fundamentally understood. This idiopathy of renal stones creates unique challenges in developing effective treatments, because a general treatment must be able to reverse formations potentially attributable to a variety of causes.
Known methods of treating kidney stones include lithotripsy, chemical irrigation for partial or complete dissolution, surgical interventions and other techniques. Lithotripsy alone is performed on about 500,000 residents of the United States every year, and the costs involved in this lithotripsy medical care and concomitant lost productivity are enormous. Other pharmaceutical compositions have been developed for treating kidney stones, with an emphasis in the historic literature on citric acid and citrate-derivatives as potentially useful to dissolve calcareous formations, presumably due to acid solubilization of the salts.
A need remains for a simple, oral outpatient treatment to reduce the size or presence of kidney stones and, on a maintenance basis, to discourage their recurrence.